I have been hacking away on replacing the PicoCSS with Simple.css, since it offer a much manageable set of color variables that can ease the work of making your own team a whole lot.
I have gotten to a place now with some sane default colors, so you are welcome to take it for a spin from: https://git.mills.io/yarnsocial/yarn/src/branch/theme_simpleCSS
There are still some issues with the mobile menu and some side-effects of using headers in places it should not have been used in the first place.
Please let me know if this is something that you see worthy of being merged into main and what you like or dislike about it as it stands now.